Your receipt identifies the subscription provider. The device or payment method alone does not.
A subscription bought through Memo's website is managed from Settings → Subscription in Memo. Paying with Apple Pay on the website does not turn it into an App Store subscription.
An Apple-billed subscription appears under the Apple Account used to purchase it. On iPhone or iPad, open Settings → your name → Subscriptions and look for Memo. Follow Apple's guide if you cannot find it.
Check your receipt or invoice for the merchant, transaction reference, billing date, amount and account. Contact Memo support with those details if you need help identifying a Memo charge.
If a receipt is for a different service with a similar name, contact the merchant shown on that receipt. Memo support can help confirm whether a charge belongs to Memo at memo.cards.
Use the provider's route for cancellation, refunds and purchase restoration. See Cancel Subscription and Refund Policy.